Tempering apparatus



Patented @et 8, 1929 JAMES CAREY DAVIS, F CHICAGO, ILLINOIS TEMPERINGAPPARATUS v Application filed November lily present invention relates tothe art ot tempering in general, more particularly to the tempering ofmetal and epecilically to 'the localized. hardening oi" steel castingscontaining' a modifying agent Broadly considered, the inventioncomprehends an improved method for tempering an aimaratue tor carryingout the tempering' method and the resiihzantl improved product.

ilhile e invention has a broad iield of ueeifilnc ,tor changing thestate ot Various article@` of different composition, l have tound it otpeculiar utility tor producing east steel ear wheels containingmanganeseaa a modifue' agent7 and I therefore lind it convenient todescribe the'invention in connection with auch product; it beingunderstood that such llimited .fieldeI oi specific description areemploj'd purely tor purposes Ot' an example Le utility of the inventionin its Several phases. f

ifhe principal objects oi the present invention are the provision of animproved method et temiiering, the provieion et an in'iproved apparatust'or tempering, the provision oi' an inmrored tempered product; theprovision ot e method eftempering characterized by a localization oi thetempering; the provieion ot' a method of tempering wherein the area ofthe tempering may be substantially controlled within predeterminedlimits; the provision of a method ot te npering characterized hy thedirection oit fluid upon predetfzrmined pointe' until all the article betempered and I a c lization of the tempering; the

provision ot' a method of tempering characterized by a differential orprogressive temperingoifthe article gthe provision of a method ottempering characterized by the employment o't means to prevent theactionby one treated l art upon another part of 'the article it ie deaired totemper; the provision. ot a method ot tempering characterized by Sotreating the surfaces ri'ing' out the Steps y t; n parte ofAx thearticles upon which the open ation ie performed as to producediiierential qualities; therein; the provision of a method f oittemp-eri j characterized hy the direction et' the treating fluid uponthe article to be 1, ieee.

may be tempered characterizedby localized areas and then treating otherareas to be tempered and car-y ot tempering with cer- Serial N'o.145,509.

tempered in general, and in paiticular means 'for directing such fiuidupon the precise area to be acted upon; the provision of a method oil",tempering characterized by the employment ot a plurality ot streams ofdifferent volume or intensity, combined with means tor controlling thetempering characteristic et the metal whereby areas oit the article maybe tempered differentially; the provision ci a method ot temperingcharacterized by the employment oft an ununit'orm quantity of temperingfluid whereby areas of the article differentially; the provision et amethod of tempering characterized by the etepe of initially treatinglocalized areas and subsequently treating the article whereby areasthereof may be differentially tempered; the provision of a method of tenperiug characterized by initially treating one portion and subsequentlytempering other portions including Said first portion without affectingthe first portiontreated; the provision ot a method ot tempering wherebylocalized areas are initially treated and then other areas treatedtogether with said first mentioned yareas, whereby differentialqualitice may be obtained by a single treatment; the proiisionoi amethod for the heat treatment o't'mctal, whereby localized areas aretreated and then subsequently utilizing the heat of the main body oi thearticle for varying' the property of the areas initially treated so thatthe areas first treated will be ot setter character than the otherareas; the provieion'of a rtempering method whereby localized areas areSucccesively treated, wherein the first treated area is of softercharacter than the subsequently treated areaa; the provision of atempering method changing the character Ot' with said localized areas toproduce a dit'- f'erentially hardened effect in which the subsequentlytreated areas are harder than the initially treated localized areas.

The invention also has for its further 0bject the provision of atemperingapparatus including means for localizing the tempering/actionupon the article which it is desired to change; the `provision 0f atemper- 100 Cil ing apparatus characterized by the horizontalejectionrot' tempering fluid so that parts may remain unmodified; theprovision tempering apparatus characterized by the einployinent of aplurality of streans olf tempering fluid whereby dierential teniperingmay be imparted to an article; the provision of a tempering ayjfparatuscharacterized by the einployinent oi treating ineans for articles to betempered, and in the further provision olineans for l ing temperingliuid'upon other areas oi arti e; the Vprovision oi tenipei" ig ratusincluding ineans Jroi' projecting; teinpering' iiuids upon localizedareas and in cluding inea-ns tor tempering` other areas; and theprovision of iinproved nieans for carrying' out the aforementionedprocesses.

ln the attainment of the tor-enjoin@ jects and certain additional benetand advantages to be herein disclosed, convenient to carry out inyrnethod by means ora an apparatus, the einbodinients o which areillustrated 'n the accompanying drawing'. On inspection ot thisdrawing', it will be observed that as above suggested? I have forpurposes of convenience 'in disclosure and description illustratedapparatus in forni adapted Jfor the treatment of a disc-like metalliccasting7 to wit: in the present case. a iianged cast manganessteel wheelof a carbon content of. .32% to .38%.

The invention is peculiarly adapted for the treatment of such objects aswill be manifest when it is considered that a great desideratuna in thehardening ot wl el treads is that such hardening be unit-erin in' orderthat the wheel may wear both uniorrnly in service and not lose itscircular character and t the saine time th i hardening' be localized tothat portion ot the tread and throat which is most usual in contact withthe rail head in order tl i the riin of the wheel inay wear uniformlyand not becoine curved in cross-section in service.

To this end, therefore, it is most desirable that the outer surface otthe naneje ot the wheel which orcinarily is 4quite or" suiiicienthardness Without tempering. be not further hardened Aand similarly. thatthe outer marginal portion or heel ol the tread which is opposite to theliange receives much less wear owing to its rel vely less Contact withthe Vrail head be lett less inedifiefl and relatively soft, so that thewheel and tread in service will wear down uni fornily.

It is likewise desirable that the web ot the center of the wheel bele'it tree from hardening and in its normal relatively soit state.

In my application. Serial No. 674.485 l have described a method andapparatus toi' obtaining a differentially hardened tread surface byshielding portions or said tread against the action ot the tempering`fluid. Vllhough this process has certain advantages outlined in theapplication aforementioned, it has been l'ound that aside troni theneces sity or" the use of inovingl partis of the agpz. tus descrised andthe necessity `for manually or otherwise applying this shield to thearticle to be tempered, that the desired shielding ehect is not obtainedto the degree desired due to conduction of heat to roi the articletreated vfitn which the shield inust corne into Contact, or by reasonoi' the tempering; lluid finding' its wa'v to the article past theiiroteciin i` shield.

lhe word tempering as employed heren, relates to changing' the state or.the inetal rested. that is it may apply to either harding or softeningorchanging' lbe relati *c tate or condition et various portions oi asingle casting' as will r-.pnear the example illustrated and describedbeing; for the purof producing; a castingr or various 'ees of hardeningin a particular region ereot. ln' the accoinpanyingr drawing, Fie'. l isa side elevation taken in section of one torni of niv teinperirapparatus;

l" 2 a Ytragrnentarv view similar to l, showingF the treatment ofanother portion o an article;

Fig. 3 is a side elevation talren in section an apparatus forprojecting' tempering an article;

is a iraginentr-iry view of the apparatus shown in. Fig. l'or treatingan article different position; M

.is a further embodiment of the apparatus shown in Fifi.

c (i is a fragmentary view or the api-Lian. tus shown in Fig'. 5 withthe article in the reverse position;

lling. 4" is a transverse sectional vieiv oit the wheel tread;

Fig. 8 is a carbon iron diagram shoving;r the variation in temperaturesand the state ot the carbon.

ln order to obtain steel wheel having a erentially ternp d treadportion. l ina v suhiect localized potions ol the tread c riin `oi'wheel cac i o' which is still above the critical i to partially vmjaction for a short period of' time; iny preferred einbodinient where awheel is to be te. ered. the heel porot the tread is treated with ateniperinoj has reached a substantially below the critical i temperaturerange.

l have 'found that in the ordinary torni of cil-st wheel. the heelportion will reach this Midition in about troni l0 to l5 seconds.

r this initial treatment. the casting is troni the influence ot thetempering removed.

y the soft portions fluid for a period of time sufficient to permit theheat of the main body of the casting to reheat the initial portiontreated. Preferably this reheating is attained'by conductionfrom themain body of the casting to the portion initially treated.

I have found that sufficient the initially treated re-heating of portionis' obtained by the casting' such as is herein preferably dealt with, ina period of about 30 seconds, and that this period of time is suflicientto overcome any structural changes which may have talfen place at theinitial quenching to render the heel portion unduly hard.

After air exposure or after the second step permitting the transferenceof yheat by conduction from the main body of the casting to the portioninitially quenched, the entire tread surface ofthe casting is then givena quenching treatment, rendering the inner surface of the flange,throat, and tread por tions extremely hard, whereas the heel por-- tionfirst treated will be found to be of such softness as will give best.operatingl results in the preferred use herein described. The effect issimilar to that produced by quenching at lower temperatures. n I havefound that quenching" .from 4. to 4% minutes is sufficient to impart thedesired hardness to the flange and tread areas and a softer effect isobtained at the heel portions or the portions which have been given.initial quenching action.y

For purposes of carrying out the proces above described, I have foundthe apparatus shown in Fig. 1 to admirably serve the purpose. i

Referring to Fig. 1, I have there illustrated a quenchimY apparatuswhich I have found to be particularly `suitable for treating car wheelsand as therein shown 1() is a pan having an annular depression, 11,defined by the upstanding walls 12 and 13 an intermediate pedestal 14arranged concentrically with the upstanding walls 12 and 13. orsupplying quenching fluid to this pan,`I provide fluid conduits 15, 16.17 and 1S arranged on either side of the annular grooves defined by thepedestal 14. There is also provided an overflow outlet 19 which may belocated to give any desired depth of overflow. The process is practisedpreferably as follows 1-T he casting, for example a car wheel, istreated while at a temperature which is above the critical range in amanner such as will be recognized to be thebest practise in suchl cases,depending upon the chemical composition of the steel that is used. Forgiving the wheel the'initial treatment, the quenching' bath may first beprepared so as to have a constant level of quenching fluid. The wheel isthen placed into the quenching pan, so that. it rests upon the pedestal14 exposing' that portion desired. to be treated to the quenching fluid,and in one embodiment of lng fluid, I have found that a and having fycasing of the same general form as the my invention the heel portion 21is first immersed into the quenching bath. As has been previouslydescribed, the wheel is left in t-he quenching bath for a period of 10to 15 seconds, where y water is used as a quenching fluid.

Though I i have described my preferred method of operation as carriedout in conn stantlevel quenching bath, I may first position the castingupon the pedestal 14 and then ygraduallv supply the quenching fluid forserving the initial quenching operation. This method of quenching willhave the function which will be apparent as the discussion proceeds.

After this initial treatment the casting is removed from the influenceof the quenching fluid to permit the re-heating of the heel portion 21by conduction of the heat of the body of the casting which in practice Ifind is ac- Coinplished satisfactorily in about 30 seconds as is abovedescribed. Thereupon, the combined areas forming the initially treatedheel portion 21 and the tread surface 22 is quenched, and where I usewater as a quenchperiod of from 4 to 41/2 minutes will give excellentresults.

Theprocess above outlined may be either for initially treating the heelportion 21, or if desired, I may initially treat the flange portion 23as shown in Fig. 2.

In this way, by a single heating of the casting, the 'separate parts maybe quenched by a series of steps, the length of time necessary forcarrying out the steps being sufficient to permit that change intemperature which will obtain best results upon subsequent quenchingaction. i

In Fig. 3, I have illustrated a quenching bath for treating the combinedareas of the wheel treated initially as above described, and thisapparatus is preferably of anature described in my application SerialNo4 670,486 in `which 24 is a casing adapted to' receive quenching fluidfrom the inlet 25 and having a plurality of series of nozzles 26, 27 and28 for projecting the quenching fluid, all this' preferably inaccordance with the apparatus described in my applicationaforementioned.

In Fig. 4, I have illustrated the apparatus above described in Fig. 3,but shown with the wheel in a reverse position, so that the flange 23 isdownwardly directed and the heel portion 21 is upwardly directed,thereby permitting the quenching fluid to gravitate away from the heelportion 21 downwardly upon the flange portion 23.

InF ig. 5, there is illustrated a further embodiment of my invention inwhich 29 is a casing above described and in my prior applicationpreviously mentioned.'` This casing is divided preferably.horizontallyby the partition wall 30 forming an upper chamber 31 and a lower chamber32.' These chambers are adapted to have separate quenching fluids fedfrom independent feeding means or conduits not shown in the drawing. TheVupper chamber 3l has a plurality of series of nozzles 33, 3f 85 similarto those shown in the embodiments illustrated in Figs. 3 and Il. VThelower chamber 35 has a series of nozzles 36. By this form of apparatus,the process may be carried out as follows The casting vis taken up atthe accustomed temperature for tempering and is then introduced withinthe confines of the tempering device 29, care being taken by vsuitablemeans to have it concentrically positioned with the general aXis of theapparatus. rlhe initial localized ytreatment is then given Vto thecasting by means of a series of jets 36,the tempering fluid bei-ngdirected against the heel portion 3l in the instance where the castingis positioned with the heel portion downw rdly directed as shown in Fig.5.

Upon the application ofthe tempering fluid 36 for a period of time, asabove described, the flow of the liquid is discontinued for a periodsufficient to permit re-heating of the initially localized area that hasbeen treated, that is to say, to permit re-heating by conduction.Subsequently, upon the expiration of the period necessary to producethis effect,the jets 33, 34: and 35 are turned on to direct thequenching liquid upon the `entire tread surface, or all the jets 33, 34,35 and 36 may be turned on to have the combined tread surface 22 andheel portion 2l submitted to the quenching action.

The series of jets 33, 34, 35 and 36 are pref erably arranged as in myapplication aforementioned so that the uppermost jet supplies a larger`quantity of quenching fluid than the lowermost series of jets. ln thisway if desired the lcontinuous surface exposed will be affected by auniform amount o quenching fluid.

In the embodiment shown in 6 the casting may occupy a reverse positionso that the flange portion Q3 is downwardly directed and is firstsubjected to the initial treatment by the lowermost series of jets 36.

In Fig. 7 there is illustrated a section of the periphery of the castwheel showing the effect of the differential tempering action in termsof the Brinell hardness scale. Thus, it will be observed that thoseportions of the tread surface which are required to be toughest indicatethe lower figures while those portions which receive the greatest wearhave the higher figures. These may be made gradient from the outermostportion receiving the greatest shock to the innermost portionwhich isapt to receive the greatest wear' in accordance with practice which willbe obvious to those skilled in the art. By thus grading the hardness inaccordance with the treatment above out-lined, uniform wear will be hadin use to retain perfect yroundness of the wheel contour throughout allof the tread surface.

ln Fig. 8 there is shown a carbon-iron diagram, the curves on whichindicate the transitions of carbon in steel when subjected to heat,followed by cooling. The upper divergence of the curve, as laid upon thescale, indicates the approximate temperature at which the carbon contentof the steel goes into solution with the iron. The lower divergence ofthe curve indicates upon the scale the approximate temperature at whichthe carbon goes out of solution with the iron, at which time pcarlite isformed.

is at a temperature above the upper critical point, since in theapplication of a quenching medium, after the temperature has fallenbelow the lower critical point and the carbon has gone out of solution,only a comparatively y When steel slight hardening action results. hasbeen heated to a temperature above the up per critical point and is thensubjected to the action ofa quenching medium, a very substantialincrease in the hardness of the steel is established and it remains insuch state until the re-application of sufficient heat to modify thesai-d hardness. The critical points of steel are modified by variationsin the chemical constitution of the steel, and therefore the curves onthe carbon-iron diagram show relate to a special composition of steelwhich l have found best suited to the production of the articles hereinmentioned.

lt is readily understood that the results obtained by me in producing acar wheel casting having a tread surface of harder characteristics thanthe localized initially treated surfaces having softer areas,-that isthe heel portion or the outer tread portion,-can be and are ascribedtothe fact that the heel or rim portion has been quenched at atemperature above the pper critical point, and would be as hard as thecenter of the tread portion were it not for the fact that theapplication of the quenching medium is of such short duration that themain body of the casting is not affected thereby, with the result thatupon cessation of application of the quenching medium to said heelportion of the tread th is a substantial reheating or return of l byconduction to the said heel portion wher eby the hardness thereof issubstantially modified, even though the said reheating or turn of heatincreases the temperature of the heel portion to exceed the lowercritical point as indicated on the diagram. The subsequent applicationof a substantial volume of water to the main tread portion of the wheelcauses great hardness thereof, but previously to this application theheel portion has been brought below the thermal point at which thefurther application of water would confer great hardness.

` The result of following the various steps lt isfknown practice toquench steel to obtain hardness while the steel x of the procedureherein indicated is that I produce an integral car Wheel Whose maintread or Wearing surface is of great hardness, and at the same time theheel or outside of tread portion of the rim is softer and more ductile,thereby establishingT a car Wheel structure Which is much stronger underimpact and which Will Wear more evenly in the regular service Which itperforms, than otherwise would be the case. y

Having thus described my invention and illustrated its use, what I claimas new and desire to secure by Letters Patent, is:

l. A tempering apparatus comprising in combination a source of temperingfluid, means for supporting a casting to be tempered on its side andmeans for applying the tempering fluid to the periphery including meansfor limiting the range of application of the tempering fluid from saidlast named means to the edges of the peripheral surface of the casting.

2. A tempering apparatus for car Wheels comprising in combination asource of tempering fluid, means for directing a plurality of strean'isof fluid from such source upon the periphery of the car wheel to betempered,

said strean'is being' operable independently of f keach ether to effectgradient tempering by application of independently controlled streams oftempering fluid.

Atempering apparatus for car Wheels or the like comprising incombination a source of tempering fluid.v means for directing` a streamof fluid from such source upon the peripheral portion of the article tobe tempered, said means having independent means of controlling the flowof fluid to direct gradient quantities of such tempering fluid to theperiphery whereby an edge portion of said peripheral portion may beindependently' treated.

et. In a tempering apparatus adapted to temper a car wheel casting,means for directf in a tempering fluid in a plurality of streams to theperiphery thereof comprising independent chambers, one of said chambersincluding means for directing a plurality yof series of streams.

5. In a tempering apparatus adapted to temper a car Wheel casting, lyingon its side, means for directing a tempering fluid to independentportions of the periphery thereof comprising independent chambers, oneof said chambers including means for direct-ing a plurality of series ofstreams arranged one above the other. f

G. In a tempering apparatus adapted to temper a car Wheel casting, lyingon itsside, means for directing a tempering fluid to independentportions of the periphery thereof, from independent sources comprisingindependent chambers, one of said chambers including means for directinga plurality of streams arranged one above the other, the uping theapplication riphery of said car permost series having' the largestvolume of streams.y y

7. A tempering apparatus for car Wheels comprising in combination asource of tempering fluid, means for directing a tempering fluidto theperipheral portion of the car Wheels and means for directing and limitofthe tempering fluid to outer edges of the peripheral portion foiltempering the peripheral portions with different intensity to otherportions of the periphery.

8. A tempering apparatus for car Wheels comprising in combination meansfor directing a'plurality of streams of fluid to thepe- Wheel includingmeans to direct and independently limit With different intensity theapplication of the tempering fluid to outer edges of said periphery.

9. A tempering apparatus for car Wheels comprising in combination meansfor directing a tempering lfluid in independent streams to differentportions of the periphery of the car Wheel, tempering fluid, one ofwhich being arranged for directing the tempering fluid to an outer edgeol the periphery for tempering the periphery of said casting withdifferent intensity.

l0. A tempering apparatus for car Wheels comprising in combination meansfor directing a tempering fluid in independent streams to differentportions of the periphery of the car WheelA independent chambers forsaid tempering fluid, one of which being arranged for directing thetempering fluid to an outer edge of the periphery of' said casting, theother of said chambers being provided with means to independently directthe tempering fluid to inner portions of said periphery of said castingwhereby temperingof different intensity of the entire periphery may beobtained.

In testimony whereof, I have hereunto signed my name this 29th day ofOctober,

JAMES CAREY DAVIS.

independent chambers for said

